A sterile and particle-free environment is a prerequisite for a diverse range of activities, e.g. when handling certain types of food, when handling laboratory samples, during the production and packaging of certain products, such as e.g. certain medicaments, foodstuffs and integrated circuits, and during surgical operations.
Surgical operations always involve the risk of transmitting potential pathogens to the patient's operation wound. Postoperative wound infections occur in approximately 7% of all surgical operations, and constitute the third most common care-related infection in Sweden. For operations in tissue free from bacteria, the risk of infection is 1-3%. Postoperative wound infections are most often caused by bacteria which contaminate the tissue during the surgical operation. The bacterial contamination may come from the patient himself (endogen infection) or from the surroundings (exogenous infection). Infectious agents may reach the operation wound through the air (air-borne infection) or through contact with e.g. instruments and liquids which have been contaminated during the operation.
Today, most surgical operations need to be carried out in special operating rooms in hospitals. These rooms are provided with ventilation which provides low levels of microorganisms in the air during the surgical operation. In addition, such ventilation minimizes the risk of inflow of microorganisms from the surrounding rooms and cleans the air after the operation. In addition, all personnel present in the operating room need to wear tight clothes to prevent skin particles carrying, potentially harmful, bacteria contaminating the air. Potential sources of contamination of the air in the operating room is e.g. when a door is opened to the operating room or, even more important, when a new person enters the room.
Due to the high demands on the surroundings during a surgical operation, many otherwise lifesaving operations which are performed under conditions where the means for providing sterile conditions are lacking, may result in the patient being infected with a potentially life-threatening infection. Such conditions may be present in disaster areas after e.g. natural disaster, refugee camps, mobile military hospitals or other areas in which the necessary equipment for providing a sterile surrounding is lacking.
During the handling and packaging of certain types of food it is very important not to contaminate the food with potentially harmful micro-organisms, since such microorganisms could lead to severe food poisoning or even intoxications such as botulism. Microorganisms may be a single cell or a multi-cellular organism. Examples of microorganism are bacteria, fungi, yeasts, archaea and protists, viruses and prions.
Samples from patients for laboratory analysis need to be handled with care and the risk of contaminating the sample with microorganisms not originating from the sample must be excluded, since such a contamination could lead to e.g. a patient being wrongly diagnosed with and treated for a disease. In addition, it is also important to reduce the risk of contaminating samples for microbiological analysis of foods for controlling the standards of hygiene in e.g. a restaurant.
Also, it is import not to contaminate medicaments during packaging, since this potentially could destroy the medicament leading to a reduction or even loss of its effect or even lead to the spreading of potentially harmful microorganisms to a patient.
One problem with current so called sterile rooms is that they in fact are not sterile due to the large areas and large amounts of equipment present in the room that needs to be cleaned and sterilized. In addition, as mentioned above, the presence of personnel in the operating room is also a potential risk of contamination. Although extensive cleaning and sterilization measures are taken, a fully sterile environment can never be achieved.